Synthetic as well as natural yarns are typically supplied as continuous yarn on bobbins. The yarn is distributed onto the bobbin by winding devices, such as for example disclosed in ‘Manual of Winding Technology’, Georg SAHM GmbH & Co., 1st ed. 1995. Winding is traditionally conducted by constant-angle cross winding (where the helix angle is kept constant) or precision cross winding (where the number of rotations of the bobbin per double stroke of the yarn guide is constant).
Also high Young's modulus yarns are typically supplied on a bobbin. Traditionally, the aim of the winding has been to provide a package with high packing density and high mechanical stability in the sense of high hardness and low tendency of the yarn to slide from the bobbin when the bobbin is arranged vertically without tension on the yarn. This is realized by winding based on closed precision cross winding the high Young's modulus yarn with a high bail pressure.